Greg is just a means to an end for Tamara. Ultimately I think that is how Greg will be redeemed, he will realise Tamara is just using him and he’ll turn on her but not before she’s royally screwed him over.
I’m fairly confident Belle will get her memory back by the end of Lacey. In the sneek peek that LaurieAnne kindly posted, Rumple tells Charming that if Charming helps him, he’ll owe Charming a favour. That’s a big thing for Rumple, especially as he doesn’t like being indebted to anyone. I wonder if Charming will call in his favour to Rumple to help get Henry back.